Method for attaching additive to polyamide pellets

ABSTRACT

A method for fixation of an additive on pellets of polyamides which comprises coating a phenol derivative of the formula:   WHEREIN R1 and R2 are each hydrogen or alkyl having not more than four carbon atoms and n is an integer of 1 to 3 with or without a polyphenol derivative of the formula:   WHEREIN X, X1 and X2 are each hydrogen, hydroxyl, alkyl having not more than 12 carbon atoms or alkoxy having not more than 12 carbon atoms, at least one of them being not hydrogen, R3 and R4 are each hydrogen, alkyl having not more than four carbon atoms or alkenyl having not more than four carbon atoms and m is an integer of 2 to 6 on the pellets and then attaching the additive thereto.

I Umted States Patent 1151 3,640,76 1

Hamanaka et al. 1 Feb. 8, 1972 [5 METHOD FOR ATTACHING ADDITIVE [57] ABSTRACT To POLYAMIDE PELLETS A method for fixation of an additive on pellets of polyamides [72] Inventors: Yams "mum; mmm Tm", both of which comprises coatmg a phenol derivative of the formula:

Tsuruga; Kunioml Etoh; Kaoru Furuhwa; 1 0 Yukito Mmi, all of Otsu, all of Japan [73] Assignee: Toyo Boseld Kabushlkl Kalsha, Osaka-shi, F

Osaka-fu, Japan l [22] Filed: Feb. 6, 1970 g R: n [21] Appl'No: 9'175 R. anJRQare eaCh hydrogen or alkyl having not 59599 1 4391 291 1111?andl wi utess p 1 w 3 wit Foreign Application Priority Data or without a polyphenol derivative of the formula:

Feb. 6, 1969 Japan ..44/9150 X on X OH I X on [52] U.S.Cl. ..117/ C, 7/69, 117/72, R3 R:

I 17/1 38.8 N, 260/45.75 C, 260/78 SC A J 51 1111. c1 ..B44d 5/00 I [58] Field ofSearch ..l l7/l00C, l6l UE, 138.8 N, R L I11 J ll7/69, 72; 260/78 SC, 45.7 SC, 857 R X1 X2 X1 X2 m X X1 1 References Cimd wherein X, X and X are each hydrogen, hydroxyl, alkyl having not more than l2 carbon atoms or alkoxy having not UNITED STATES PATENTS more than 12 carbon atoms, at least one of them being not 2,996,466 8/1961 Kessler et al ..ll7/l00X hydrogen, R and R4 are each hydrogen, alkyl having not 3,156,665 11/1964 Brossman et al. ....1 17/100 X more than 4 carbon atoms or alkenyl having not more than 2,790,734 4/1957 Kuhn et al ..l l7/l38.8 X gear hon atoms and m is a n integer of 2 to 6 on the pellets 3,086,960 4/1963 Bletso.... ..260/78 X and he ua hi th dditi fie F a" 3,207,620 9/1965 Roth .1 l7/l38.8 X 3,280,052 l0/l966 Wantanabeet al ..260/45.7 S

FOREIGN PATENTS OR APPLICATIONS 0 911,800 ll/l962 Great Britain ..117/100 7Claims, 1 Drawingilgure Primary Examiner-Murray Katz Assistant ExaminerMathew R. P. Perrone Att0rneyCraig, Antonelli & Hill TEMPERATURE (c) VISCOSITY IPOISE) PATENTEDFEB 8 i972 3.640.761

TEMPERATURE (c) lo' I00 |0' |0 I0 VISCOSITY (P0|SE)' mvEmoR YASUSHI HAMANAKA HIROMI mum KAORU FURUKAWA KUNIOMI ETOH vumo MASAI BY 4am, ATTORNEYS METHOD FOR ATTACHING ADDITIVE TO POLYAMIDE PELLETS The present invention relates to a method for attaching a powdery or liquid additive to the surface of pellets of polyamides.

The drawing shows the relationship between the temperature and the viscosity of the support material.

On the production of fibers, films, injection-molding articles and the like from pellets of polyamides, various additives such as antioxidizing agents, pigments, light stabilizers, dyestuffs, fireproof agents, nucleating agents, and transparent agents are incorporated therein. In such case, the additives are usually attached on the pellets by the aid of a support material having adhesive property for assurance of the uniform dispersion in the products. For instance, a lower molecular weight polyamide, adiponitrile or the like has been used for fixing pigments on pellets of polyamides. A high melting point polymer provides a strong adhesive power, but such substance is required to apply in the form of solution or in the melt state. Further, the additives are obliged to be attached at a temperature higher than the melting point of the support material. Thus, the operation for surface treatment becomes complex and troublesome. On the other hand, a substance such as adiponitrile may be reacted with the polyamides or decompose the additives when the pellets are melted. Moreover, the adhesive power is not so strong and the application field is considerably limited.

As the result of the study seeking a support material for fixing additives on pellets of polyamides, which has an appropriate affinity to the pellets, provides an excellent adhesive power and extends well the additives on the pellets at a relatively low temperature, it has been found that a phenol derivative of the formula:

wi l

wherein X, X and X are each hydrogen, hydroxyl, alkyl having not more than 12 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, butyl, octyl, dodecyl) or alkoxy having not more than 12 carbon atoms (e.g., methoxy, ethoxy, propoxy, isopropoxy, butoxy), at least one of them being not hydrogen, R and R are each hydrogen, alkyl having not more than four carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, butyl) or alkenyl having not more than four carbon atoms e.g., allyl, butenyl) and m is an integer of 2 to 6. The present invention is based on the above finding.

According to the present invention, the fixation of an additive on pellets of polyamides is carried out by coating the phenol derivative [1] with or without the polyphenol derivalive it on the pellets mid tlwn attaching the additive thereto.

As the phenol derivative 1 l I, there may he usually employed styrenated phenol (a mixture of the styrene adducts of phenol wherein the number of the substituents is one to three). Still, in the formula [I], the phenylalkyl substituent(s) may be present at any position(s) of the 0-, m-, and p-positions to the hYQPllEQEB The polyphenol derivative [II] is the reaction product of a substituted phenol with an alkyne, an aldehyde or a ketone specific examples of the phenol portion are methylallylidene, butenylidene, l-methylethylidene, l-methylbutylidene, l-ethylbutylidene, etc. Still, in the formula [II], all the substituents other than the hydroxyl group may exist at any positions of the o-, m-, and p-positions to the hydroxyl group on the benzene ring.

The temperature under which the coating and attaching operations are carried out may be appropriately decided on the viscosity of the support material. For instance, the relationship between the temperature and the viscosity of the support material consisting of a mixture of styrenated phenol as the phenol derivative [I] and the condensation product of ppropylphenol with acetaldehyde (m=3) as the polyphenol derivative [II] is shown in the logarithmic graph of the accompanying drawing wherein the solid lines I, 2, and 3 are respectively for the mixtures at weight ratios of 1:0, 4:1 and 2:1. From the graph, it is understood that the support material can be varied widely in viscosity, i.e., from an entirely fluidizable liquid to a highly viscous liquid, within a relatively narrow scope of temperature by selecting a suitable composition of the support material. Thus, even coated pellets of high fluidizability are readily obtainable by treating the uncoated pellets with the said support material at about C.

In practice, 100 parts by weight of the pellets are first coated with 0.05 to 0.5 part by weight of the support material consisting of the phenol derivative [I] alone or of a mixture of the phenol derivative [I] and the polyphenol derivative [II] at 80 to C. for about 20 to 30 minutes in a rotating drum and then one or more additives are added thereto under rotation so as to attach the additives uniformly to the said pellets.

When the support material consists of a mixture of the phenol derivative [I] and the polyphenol derivative [II], the weight ratio may be from 2:10 to 20zl0, preferably from 5:10 to 20:10. The amount of the additive depends on its kind. For instance, the copper salt of an organic acid is ordinarily attached to the pellets in 0.05 to 0.1 percent by weight (in terms of copper) on the basis of the latter. Further, for instance, 2-mer captobenzimidazole is normally attached in 0.1 to 1.0 percent by weight to the pellets.

The said coating and attaching operations may be effected, if necessary, with repetition. Further, when the additive is liquid, it may be previously incorporated into the support material so that coating and attaching are accomplished in a single operation.

Compared with known support materials, the phenol derivative [I] is advantageous in chiming no coloration to llir products manufactured from the pellets coated lhflfllly. I'Iu: combined use of the polyphenol derivative [II] is particularly advantageous in increasing the fatigue resistance and strengthening the adhesive power.

Practical and presently preferred embodiments of the present invention are illustratively shown in the following examples wherein parts are by weight.

The coefficient of dynamic friction is determined by the method described in Kagaku Kogaku (Chemical Engineering)," Vol.24, pp. 205 to 213 (1960).

EXAMPLE 1 In a rotary evaporator, there are charged 200 parts of dried cylindrical pellets of polycapramide (molecular weight, 23,500) of 2 mm. in diameter and 2 mm. in length, and 0.2 part of 2-(a-methylbenzyl)phenol is added thereto. The evaporator is rotated at about 50 C. for about 20 minutes so that the support material is attached uniformly to the pellets. l 5

One part of powdery copper acetate of less than 300 mesh is introduced into the evaporator, which is then rotated at about 50 C. for 20 minutes. The pellets are cooled, moved into a sieve of 20 mesh screen and shaken at an amplitude of 20 mm.

with a frequency of 240 per minute for minutes. Then, the

pellets are subjected to melt spinning by the use of an extruder. The resultant filaments contain 98 percent by weight of the employed acetate copper dispersed uniformly.

For comparison, the above operations are carried out but using no support material. The resulting filaments include only 2 5 10 to percent by weight of the employed copper acetate with unevenness.

EXAMPLE 2 and the compression fatigue on the tire cords made of the filaments are shown in thefollowing table; 7 I

TABLE Example 4 To 200 parts of pellets of polyhexamethylene adipamide (molecular weight, 15,000) of1.5 mm. in diameter and 1.5 mm. in length, 1.2 parts of styrenated phenol are added. and the resultant mixture is mixed up at C. A mixture of 1.0 part of xylenol-acetaldehyde condensate (m=2 or 3) and 0.3 part of carbon black is attached to the pellets. The resultant pellets are supplied to a screw-spinning machine by the aid of a vibration feeder without elimination of the additive in a transportation pipe.

What is claimed is:

1. In a method for the fixation of at least one additive on pellets of polyamides wherein a support material is first coated onto the pellets followed by a coating of at least one additive, an improvement wherein'the support material is a phenol derivative of the formula:

wherein R, and R are each hydrogen or alkyl having not more than 4 carbon atoms and n is an integer of l to 3.

2. The method according to claim 1, in which the amount of the phenol derivative is 0.05 to 0.5 percent by weight to the pellets.

3. The method according to claim 1, in which the phenol derivative is used together with a polyphenol derivative of the formula:

wherein X, X,, and X are each hydrogen, hydroxyl, alkyl having not more than 12 carbon atoms or alkoxy having not mo e Auxiliary support material cioeflgt- I Retenzionf Goodlich. 0 en 0 re. a o compres- 1 X X X2 in X X Amount dynamic copper sion used friction acetate fatigue X X X? R; R4 1n (parts) (rid) (percent) (percent) 0. 6 0. 32 98 68 H... II t-C4Hp(p-pos1t1on) H.. OH; 4 1.0 0.22 100 79 1 2. 0 0 19 100 80 II... GU 0... t-CiHQ H... CH3 6 1.0 0 20 99 78 1. 5 0 16 100 78 N.-." ll HO(p-p0s1tlon) H"... 1-methylethyl1dene 2-6 1.0 0 31 95 74 1. 5 0 28 96 77 Fundamental support materlal alone 0. 52 98 63 N0 support material 0. 15 64,

EXAMPLE 3 In a rotary evaporator, there are charged 100 parts of cylindrical pellets of polymetaxylylene adipamide (molecular weight, 10,500) of 1.5 mm. in diameter and 2 mm. in length,

and the evaporator is heated at to C. 0.4 part of a support material consisting of a mixture of styrenated phenol and p-t-butylphenol-acetaldehyde condensate (m=2 or 3) in a molar ratio of 1:1 is heated at to C. and added to the said pellets. The resultant mixture is mixed up for about 20 70 12 carbon atoms, at least one of them being not hydrogen, R and R are each hydrogen, alkyl having not more than four carbon atoms or alkenyl having not more than four carbon atoms and m is an integer of 2 to 6.

4. The method according to claim 3, in which the weight ratio of the phenol derivative and the polyphenol derivative is from 5:10 to 20:10.

5. The method according to claim 3, in which the amount of the phenol derivative and the polyphenol derivative is 0.05 to 0.5 percent by weight to the pellets.

6. The method according to claim 3, in which the additive is the copper salt of an organic acid.

7. The method according to claim 3, in which the additive is 75 2-mercaptobenzimidazole. 

2. The method according to claim 1, in which the amount of the phenol derivative is 0.05 to 0.5 percent by weight to the pellets.
 3. The method according to claim 1, in which the phenol derivative is used together with a polyphenol derivative of the formula:
 4. The method according to claim 3, in which the weight ratio of the phenol derivative and the polyphenol derivative is from 5:10 to 20:10.
 5. The method according to claim 3, in which the amount of the phenol derivative and the polyphenol derivative is 0.05 to 0.5 percent by weight to the pellets.
 6. The method according to claim 3, in which the additive is the copper salt of an organic acid.
 7. The method according to claim 3, in which the additive is 2-mercaptobenzimidazole. 